Serialization
The resulting document of a collection is serialized before being written to the file system. This process ensures the document can be stored in a file and later read back into memory. To serialize the document, the resulting object must be serializable, meaning it can only consist of the following types:
- String
 - Number
 - Boolean
 - Null
 - Undefined
 - Date
 - Map
 - Set
 - BigInt
 - Array of serializable types
 - Object with serializable values